1. Field of the Invention
The present invention relates to an indwelling needle, and specifically, to an indwelling needle comprising a needle housed in a protective cover in a housed state.
2. Description of the Related Art
Currently a puncture is made in a patient with an indwelling needle for an intravenous drip infusion, dialysis, or the like. In this case, it is necessary to prevent the indwelling needle removed from the patent from accidentally sticking in a healthcare professional.
Thus, known indwelling needles comprise a needle having a sharp edge formed at its tip, a cylindrical hub at a proximal end of the needle, and a cylindrical protective cover that can be advanced and retracted along the needle (Patent Documents 1-3).
The indwelling needle in Patent Document 1 (Japanese Patent Laid-Open No. 10-85333) is composed of a hub that retains a proximal end of a cannula and a retention cylinder in which the hub is housed and held. The retention cylinder is advanced and retracted to house the cannula in the retention cylinder.
The indwelling needle in Patent Document 2 (Japanese Patent Laid-Open No. 2002-330945) is composed of a hub provided at a proximal end of a needle cannula and a safety shield that slidably houses the hub. In a use state, operating an actuator advances a spring elastically installed between the hub and the safety shield to house the safety shield in the needle cannula.
The indwelling needle in Patent Document 3 (Japanese Patent Laid-Open No. 2003-180829) is composed of a needle assembly made up of a needle cannula and a needle hub and a body portion that houses the needle assembly so that the needle assembly can be advanced and retracted. After the medical treatment is finished, a sticking element is stored in the body portion under the elastic force of a spring with operating an actuation button.
Thus, by using the indwelling needles in Patent Documents 1-3, after use, the above accident is prevented by storing the needle in the protective cover to establish a housed state.
However, the indwelling needles in Patent Documents 1-3 need to make the protective cover which is longer than a part of the needle projecting from the protective cover. This results in an unavoidable increase in the length of a member fixed to the patient in a use state.
In this case, for example, for a patient under a dialysis treatment, repeatedly making a puncture with the needle causes the tissue in the punctured part to be hardened, resulting in a lump-like swelling. Then, the long member fixed to the patient in the use state may come into contact with the swelling to cause the needle to be inserted into the vessel at an inappropriate angle. As a result, the patient expresses pain.